/**
* This function takes an array of strings and turns it into the sqlKey. It does this by iterating through the
* array, running the string through sqlite_escape_string() and then combining that string to the keystring with a
* delimiter.
*
* @param array $key
* @return string
*/
public static function makeSqlKey($key)
{
$key = ehough_stash_Utilities::normalizeKeys($key, 'base64_encode');
$path = '';
foreach ($key as $rawPathPiece) {
$path .= $rawPathPiece . ':::';
}
return $path;
}
/**
* Turns a key array into a key string. This includes running the indexing functions used to manage the Redis
* hierarchical storage.
*
* When requested the actual path, rather than a normalized value, is returned.
*
* @param array $key
* @param bool $path
* @return string
*/
protected function makeKeyString($key, $path = false)
{
$key = ehough_stash_Utilities::normalizeKeys($key);
$keyString = 'cache:::';
$pathKey = ':pathdb::';
foreach ($key as $name) {
//a. cache:::name
//b. cache:::name0:::sub
$keyString .= $name;
//a. :pathdb::cache:::name
//b. :pathdb::cache:::name0:::sub
$pathKey = ':pathdb::' . $keyString;
$pathKey = md5($pathKey);
if (isset($this->keyCache[$pathKey])) {
$index = $this->keyCache[$pathKey];
} else {
$index = $this->redis->get($pathKey);
$this->keyCache[$pathKey] = $index;
}
//a. cache:::name0:::
//b. cache:::name0:::sub1:::
$keyString .= '_' . $index . ':::';
}
return $path ? $pathKey : md5($keyString);
}
/**
* This function takes in an array of strings (the key) and uses them to create a path to save the cache item to.
* It starts with the cachePath (or a new 'cache' directory in the config temp directory) and then uses each element
* of the array as a directory (after putting the element through md5(), which was the most efficient way to make
* sure it was filesystem safe). The last element of the array gets a php extension attached to it.
*
* @param array $key Null arguments return the base directory.
* @return string
*/
protected function makePath($key = null)
{
if (!isset($this->cachePath)) {
throw new ehough_stash_exception_LogicException('Unable to load system without a base path.');
}
$basePath = $this->cachePath;
if (count($key) == 0) {
return $basePath;
}
// When I profiled this compared to the "implode" function, this was much faster. This is probably due to the
// small size of the arrays and the overhead from function calls. This may seem like a ridiculous
// micro-optimization, but I only did it after profiling the code with xdebug and noticing a legitimate
// difference, most likely due to the number of times this function can get called in a scripts.
// Please don't look at me like that.
$memkey = '';
foreach ($key as $group) {
$memkey .= str_replace('#', ':', $group) . '#';
}
if (isset($this->memStore['keys'][$memkey])) {
return $this->memStore['keys'][$memkey];
} else {
$path = $basePath;
$len = floor(32 / $this->directorySplit);
$key = ehough_stash_Utilities::normalizeKeys($key, $this->keyHashFunction);
foreach ($key as $value) {
if (strpos($value, '@') === 0) {
$path .= substr($value, 1) . DIRECTORY_SEPARATOR;
continue;
}
$sLen = strlen($value);
$len = floor($sLen / $this->directorySplit);
for ($i = 0; $i < $this->directorySplit; $i++) {
$start = $len * $i;
if ($i == $this->directorySplit) {
$len = $sLen - $start;
}
$path .= substr($value, $start, $len) . DIRECTORY_SEPARATOR;
}
}
$path = rtrim($path, DIRECTORY_SEPARATOR) . '.php';
$this->memStore['keys'][$memkey] = $path;
// in most cases the key will be used almost immediately or not at all, so it doesn't need to grow too large
if (count($this->memStore['keys']) > $this->memStoreLimit) {
foreach (array_rand($this->memStore['keys'], ceil($this->memStoreLimit / 2) + 1) as $empty) {
unset($this->memStore['keys'][$empty]);
}
}
return $path;
}
}
/**
* Turns a key array into a key string. This includes running the indexing functions used to manage the memcached
* hierarchical storage.
*
* When requested the actual path, rather than a normalized value, is returned.
*
* @param array $key
* @param bool $path
* @return string
*/
protected function makeKeyString($key, $path = false)
{
$key = ehough_stash_Utilities::normalizeKeys($key);
$keyString = ':cache:::';
$pathKey = ':pathdb::';
$time = microtime(true);
if ($time - $this->keyCacheTime >= $this->keyCacheTimeLimit) {
$this->keyCacheTime = $time;
$this->keyCache = array();
}
foreach ($key as $name) {
//a. cache:::name
//b. cache:::name0:::sub
$keyString .= $name;
//a. :pathdb::cache:::name
//b. :pathdb::cache:::name0:::sub
$pathKey = ':pathdb::' . $keyString;
$pathKey = md5($pathKey);
if (isset($this->keyCache[$pathKey])) {
$index = $this->keyCache[$pathKey];
} else {
$index = $this->memcache->cas($pathKey, 0);
$this->keyCache[$pathKey] = $index;
}
//a. cache:::name0:::
//b. cache:::name0:::sub1:::
$keyString .= '_' . $index . ':::';
}
return $path ? $pathKey : md5($keyString);
}
